U.S. Missile Intercept Test 'a Success'

The U.S. says it has succeeded in testing a defense system intercepting intercontinental ballistic missiles from North Korea or Iran in the exosphere. The exosphere is the outermost layer of Earth's atmosphere at an altitude of more than 500 km.

In a Boeing-run Ground-based Midcourse Defense system on Sunday, a 5-feet-long (about 152 cm) "kill vehicle," detached from a ground-based interceptor missile precisely hit a target missile launched from a test site on Kwajalein Atoll west of the Marshall Islands in the Pacific toward the U.S. mainland, the Pentagon said.

The interceptor was launched from Vandenberg Air Force Base in California. A kill vehicle must fly at a speed of more than Mach 20 to intercept an incoming missile.

It was the first time in six years that the U.S. has succeeded in a GMD test. The interceptor made by Raytheon is an improved version of an earlier kill vehicle that failed in two tests in 2010.

To counter the threat of intercontinental missiles from North Korea and Iran, the U.S. conducted 16 GMD tests between 1999 and 2013, but it had a poor success rate of 50 percent despite costing more than US$40 billion.

The latest success will boost Washington's plans to build a Terminal High Altitude Area Defense (THAAD) system, which it is likely to pressure Seoul to join.